Reverend Mother Montemagni was a Bene Gesserit Reverend Mother and sister who lived on Kaitain. She was among the Bene Gesserit sisters who stayed at the Imperial Court, and her duty was to train Imperial Princess Josifa Corrino in the Bene Gesserit ways. Rivalry, always present between Josifa and her sister Wensicia, led the latter to request the help of the Imperial Truthsayer Reverend Mother Gaius Helen Mohiam. Mohiam taught Wensicia some Bene Gesserit tricks in order to defeat Josifa, however, her tricks produced no effect, as Josifa was taught by Montemagni how to avoid Wensicia's tricks and counter-attack them.